Fluidic device

ABSTRACT

This disclosure describes a fluidic device which includes a primary supply orifice and a collector orifice with the collector orifice spaced from and generally confronting the primary supply orifice. Primary supply air is discharged from the primary supply orifice to form a primary airstream which flows into the collector orifice. To protect the primary airstream against ambient air currents, a protective fluid column at least partially surrounds the primary airstream and extends therealong to serve as a shield. The primary airstream may be disrupted or deflected in response to the presence or absence of the object which is being sensed. The presence or absence of a predetermined flow or pressure of primary air through the collector passage provides a signal indicating the presence or absence of the object.

United States Patent [72] Inventor Franklin C. Eickenhorst 3,425,433 2/1969 Moore 137/81.5 Mason,0hio 3,426,781 2/1969 Neuman 137/81.5 [21]Appl. No. 794,242 3,468,028 2/1969 Howie,Jr. l37/81.5 [22] Filed Jan.27, 1969 [45] Patented May 25, 1971 :Z g fi g i g 73 Assignee DaytonReliable T0018: Mfg. Company amey L [54] f 1C1? ABSTRACT: Thisdisclosure describes a fluidic device which 8, rawlns s includes aprimary supply orifice and a collector orifice with [52] U.S.Cl 137/81.5the collector ifi Spaced f m and generally f ti [51] InLCl F15c 1/04 theprimary supply ifi primary supply is discharged [50] Fleld of Search137/8l.5 f the primary Supply ifi to form a rimary airstream which flowsinto the collector orifice. To protect the primary [56] References cuedairstream against ambient air currents, a protective fluid UNITED STATESPATENTS column at least partially surrounds the primary airstream and3,258,023 6/ 1966 Boules 137/81.5 extends therealong to serve as ashield. The primary airstream 3,262,468 7/1966 Metzger 137/81.5 may bedisrupted or deflected in response to the presence or 3,272,215 9/1966Bjornsen et a1 137/81.5 absence of the object which is being sensed. Thepresence or 3,277,915 10/1966 Dockery 137/81.5 absence of apredetermined flow or pressure of primary air 3,367,350 2/ 1968 Howland137/81.5 through the collector passage provides a signal indicating the3,398,758 8/1968 Unfried 137/81.5 presence or absence of the object.

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i I kf 3 all/foal L L 6 e/r/e/1/ L 3 j 39 Z5 23 I Patented May 25, 1971FLUIDIC DEVICE BACKGROUND OF THE INVENTION In many production andmanufacturing operations it becomes necessary to sense or detect thepresence or absence of an object or a component thereof at variouslocations along the production line. Following the detection operation,it may be desirable to actuate or shut down various pieces ofcquipmentdepending upon whether or not an object is missing. For example, if anobject or part is not present, it may be desirable to shut down theproduction equipment or to actuate other equipment which removes thefaulty unit from the production line. Alternatively, it may be desirableto count the number of objects or parts and this can be accomplished bya suitable counter which adds the number of objects which are sensed.

Because of its simplicity and low cost, a fluidic sensor and fluidicsystem can advantageously be used to perform the sensing and relatedfunctions. In one type of fluidic sensor, a primary airstream emanatesfrom a primary supply orifice and traverses a gap between the primarysupply orifice and a collector orifice. At least some of the primaryairstream enters the collector orifice to provide a signal to a fluidiccontrol element or output device which may be responsive to either flowor pressure or the absence thereof. To accomplish the sensing ordetecting function, a series of objects are passed sequentially throughthe primary airstream with each of the objects operating to disrupt theprimary airstream and with the primary airstream automaticallyreestablishing itself after such object has been passed completelytherethrough. Thus, as the series of objects are passed through theprimary airstream, the primary airstream provides air pulses to thecollector orifice, which pulses will last for a predetermined timeperiod This pulsed output may actuate the fluidic control element witheach pulse as where the control element is a counter or a portionthereof. Alternatively, the pulses may be of such short duration thatthe conduit to the c4ntrol element does not become sufficientlypressurized unless one of the objects is missing or incomplete in whichevent the pulse is of sufficient duration to actuate the output device.In this latter event, the control element may be a fluidic amplifier andthe pressure of the primary air as a result of a missing object maycause actuation of removal equipment to remove the incomplete object, orshut down the production equipment, etc.

In another form of fluidic sensor, the primary airstream is disrupted bya secondary airstream and the objects are passed through the secondaryairstream to deflect the latter. This type of fluidic sensor isdescribed in applicant's copending patent application Ser. No. 742,361,entitled Fluidic Eye, and now abandoned.

Fluidic sensors of this type work very well; however, problems can arisewhen the sensor is used in an environment having significant ambient aircurrents. Such currents are not uncommon in industrial plants and may becaused, for example, by open windows in the building, ventilation fans,closely adjacent moving objects, etc. Ambient air currents of sufficientvelocity and/or pressure can disrupt the primary airstream and therebyprovide a false signal to the fluidic control element. Such false signalmay provide false actuation of the output element and significantlyupset the production operation. Furthermore, the continued presence ofsuch ambient air currents would make the otherwise highly desirablyfluidic sensing system virtually inoperative.

SUMMARY OF THE INVENTION The present invention solves the problem ofambient air currents by providing a protective fluid layer which shieldsthe fluid or primary air stream against deflection or disruption byambient air currents. The protective layer should extend along the airstream on the sides thereof subject to disruption by the ambientcurrents. Where ambient currents may come from all sides, the protectivelayer is preferably in the fonn of a protective tubular column whichsurrounds the airstream and extends substantially the full length of theairstream. Although the protective layer can be used to protect manydifferent unconfined fluidic streams, it is particularly adapted for usewith a fluidic sensor.

The present invention teaches that the protective fluid column can beformed by diverting a portion of the primary air stream adjacent thecollector orifice. This can be advantageously accomplished by adeflector or diverter which is mounted adjacent the collector orificeand which reverses the direction of flow of such portion of the primaryairstream and causes the latter to return toward the primary supplyorifice. In order to so deflect the portion of the primary airstream,the diverter preferably includes a concave surface which extendscompletely around the collector orifice. More specifically, the curvedsurface is preferably annular with the axis of the collector orificecoinciding with the axis of the annular surface. In axial cross section,the curved surface is concave or forms a recess which opens generallytoward the primary supply orifice.

The area of the collector orifice must be sufficiently small in relationto the cross-sectional area of the primary airstream when such airstreamreaches the collector orifice so that only a portion of the primaryairstream will enter the collector orifice. Preferably, the centralportion of the primary airstream enters the collector orifice and aperipheral region of the primary airstream is deflected by the diverter.To provide this result, the area of the collector orifice is preferablyabout 20 percent less than the area of the supply orifice.

The invention, both as to its organization and method of operationtogether with further features and advantages thereof may best beunderstood by reference to the following description taken in connectionwith the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a semidiagrammatic top planview of a fluidic system embodying a fluidic sensor constructed inaccordance with the teachings of this invention.

FIG. 2 is a side elevational view of the sensor.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1 andillustrating the diverter on an enlarged scale.

FIG. 4 is a front elevational view of the diverter.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and inparticular to FIGS. 1 and 2 thereof reference numeral 11 designates afluidic sensor constructed in accordance with the teachings of thisinvention. The sensor 11 includes a body member 13 which may be anintegral block of plastic or other suitable material and which issuitably supported as by a supporting surface 14 (FIG. 2). The bodymember 13 includes block portions 15 and 17 which are preferablyintegrally joined by a web 19. A diverter 21 may be formed integrallywith the block portion 15 or may be formed separately and affixedthereto as by a connector 23.

The body member 13 has a primary air supply passage 25 therein whichterminates at one end in a primary supply orifice 27. The passage 25 ispreferably generally cylindrical and the primary supply orifice 27 ispreferably generally circular and of lesser diameter than the passage25. The orifice 27, in the embodiment illustrated terminatessubstantially flush with an inner face 29 of the block portion 17.

The primary supply passage 25 is connected by a conduit 31 to a tank 33or other suitable means for containing a source of primary air underpressure. The conduit 31 is releasably connected to the body member 13by a suitable coupling 35. The pressure in the tank 33 can be maintainedwithin prescribed limits by a pump 37. The pressure of the primary airin the passage 25 is preferably between I p.s.i. and 5 psi, so that theair discharged from the primary supply orifice 23 will be in the form ofa confined airstream or column 39.

The body member 13 also defines a collector passage 41 which terminatesat one end in a collector orifice 43 with the collector orifice in theembodiment illustrated, being formed by the diverter 21. The orifices 27and 43 are in spaced, generally confronting relationship, and in theembodiment illustrated, these orifices as well as the passages 25 and 41are coaxial.

A conduit 45, which may be releasably coupled to the body member 13 by acoupling 47 provides a flow path between the collector passage 41 and afluidic control element or a fluidic output device 49. The output device49 is a fluidic device of the type which can be actuated by the primaryairstream 39 when such primary airstream is transmitted thereto via thepassage 41 and the conduit 45. For example, the output device 49 may bea fluid amplifier which operates or actuates other equipment or it maybe a counting device.

The primary function of the diverter 21 is to provide a protective fluidcolumn 51 for protecting and shielding the primary airstream 39 againstair currents. The diverter 21 contains the collector orifice 43 at acentral location and, depending upon the axial length of the diverter21, the collector passage 41 may also extend into the diverter in whichevent, the orifice 43 would only extend part of the way through thediverter. The diverter 21 may have a circular periphery as shown in FIG.4 and a planar rear face 53 as shown in FIG. 3. The diverter has acurved surface 55 on the forward end thereof which intercepts anddiverts a peripheral portion of the primary airstream 39. The surface 55is concave as viewed in H6. 3 and defines a recess or cavity 57 whichopens generally toward the primary supply orifice 27. The curved surface55 preferably extends completely around the collector orifice 43 and ispreferably annular as viewed in front elevation (FIG. 4). The diverter21 also has a radially narrow annular flat surface 59 the plane of whichis generally perpendicular to the axis of the orifice 43.

With the primary air flowing through the primary supply orifice 27, anunconfined primary airstream 39 is directed toward the collector orifice43 with the cross-sectional area of the primary airstream increasing asit approaches the collector orifice. The collector orifice 43 is sizedso that the area thereof will be less than the cross-sectional area ofthe primary airstream when it reaches the collector orifice.Accordingly, a central portion of the primary airstream can enter thecollector orifice 43 whereas a peripheral portion of the primaryairstream 39 is directed to the curved surface 55 which reverses itsdirection and forms the protective column 51. As the surface 53 isgenerally annular in front elevation, the column 51 is also generallyannular with the air therein flowing from the diverter 21 generallytoward the block portion 17 and with the primary airstream 39 beinggenerally centrally disposed within the protective column. Thus, theaxes of flow of the primary airstream and the protective column extendgenerally in the same direction.

With this arrangement, ambient air currents are first met and themselvesdeflected by the protective column 51. That is, before ambient aircurrents can be felt by the primary airstream 39, at least some of theenergy therein must first be dissipated by destruction of the protectivecolumn 51. With ambient air currents of the type normally encountered inindustrial applications, such dissipation of energy renders theminnocuous with respect to the primary airstream 39.

It will be apparent to those having ordinary skill in the art that thediverter concept as described herein is applicable in many instanceswhere it is desired to protect a fluidic column against ambient or otherair currents. For illustrative purposes, however, FIG. 1 shows thediverter 21 being utilized in connection with a fluidic sensor which inturn is being used to sense the presence or absence ofa plurality ofobjects 61. The objects 61 are arranged on a suitable surface such as aconveyor 63 which moves the object 61 sequentially across the path ofthe primary airstream 39,

As the first of the object 61 reaches the path of the primary airstream39, the primary airstream is disrupted so that it cannot flow into thecollector orifice 43; however, when the first of the objects 61 hascompletely passed through the path of the primary airstream, the primaryairstream quickly reestablishes itself so that flow into the collectororifice is now possible. Thus, as each of the objects 61 moves throughthe path of the primary airstream, the air supply from the orifice 27 tothe output element 49 is cut off. Stated differently, a pulse of air issupplied to the collector orifice 43 whenever no object is in the pathof the primary airstream 39. Should one or more of the objects 61 bemissing, air would be supplied to the output element 49 for a sufficientperiod and under sufficient pressure to actuate the output elementtocause the appropriate control action to occur.

Although exemplary embodiments of the invention have been shown anddescribed, many changes, modifications and substitutions may be made byone having ordinary skill in the art without necessarily departing fromthe spirit and scope of this invention.

1 claim:

1. In a fluidic device for sensing the presence or absence of an object,the combination of:

a body member having first and second faces, said faces being generallyconfronting and spaced apart said body member having a primary airsupply passage therein connectable to a source of primary air underpressure, said primary air supply passage terminating adjacent saidfirst face in a primary supply orifice with the primary air beingdischarged from the primary supply orifice in a primary airstream;

said body member having a collector passage therein, said collectorpassage having a collector orifice which is adjacent said second faceand which is spaced from said primary supply orifice, said collectororifice being arranged to receive air from the primary airstream; and

means defining a curved surface adjacent said collector orifice and inthe path of said primary airstream for diverting a portion of theprimary airstream into a generally tubular protective, air columnextending along and at least substantially surrounding the primaryairstream to protect the latter against ambient air currents.

2. A combination as defined in claim 1 wherein said last mentioned meansincludes a deflector member mounted on said body member, said deflectormember having said collector orifice therein and defining said curvedsurface.

3. A combination as defined in claim 1 wherein said last mentioned meanscauses the air of the protective column to flow in a direction generallyopposite to the direction of air flow of the primary airstream.

4. In a fluidic system, the combination of:

means defining a primary fluid supply passage, said primary fluid supplypassage defining a primary supply orifice which is capable ofdischarging fluid therefrom in a pri mary fluid stream;

means defining a collector passage, said collector passage defining acollector orifice which generally confronts said primary supply orificeand is spaced therefrom by a gap so that at least a portion of theprimary fluid stream discharged from said primary supply orifice cantravel across said gap to said collector orifice; and

means defining a curved surface adjacent said collector orifice and inthe path of said primary fluid stream for divert ing a portion of theprimary fluid stream into a generally tubular, protective, fluid columnextending along and at least substantially surrounding the primary fluidstream to protect the latter against ambient fluid currents.

5. A combination as defined in claim 4 wherein said curved surfacesurrounds the collector orifice and defines a generally annular recessopening toward said primary supply orifice.

6. In a fluidic device for sensing the presence or absence of an objectand connectable to a fluidic control element, the combination of:

means defining a primary fluid supply passage terminating adjacent oneend in a primary supply orifice with the primary supply orifice beingcapable of discharging fluid therefrom in a primary fluid stream;

means defining a collector passage connectable to the fluidic controlelement and terminating adjacent one end in a collector orifice, saidcollector orifice generally confronting said primary supply orifice andbeing spaced therefrom by a gap of predetermined length so that at leasta portion of the primary fluid stream discharged from said primarysupply orifice can traverse said gap and enter said collector orifice toprovide a first signal for the fluidic control element; and

means adjacent said collector orifice for converting a portion of theprimary airstream into a protective column of fluid extending along andat least partially surrounding the primaryfluid stream to protect thelatter against ambient air currents, disruption of the primary fluidstream for a predetermined period providing a second signal to thefluidic control element.

7. A fluidic device, comprising:

a collector having a collector passage therein, said collector passagehaving a collector inlet;

means including a discharge opening with the discharge opening beingspaced from the collector inlet by a gap for directing a substantiallyunconfined fluidic stream from the discharge opening across said gap tothe collector inlet; and

diverter means adjacent said collector inlet for intercepting a portionof the fluidic stream and converting at least some of said portion ofthe fluidic stream into a protective layer which extends along and atleast partially surrounds said fluidic stream with the axis of flow ofsaid protective layer extending generally in the same direction as theaxis of flow of the fluidic stream.

8. A fluidic device as defined in claim 7 wherein said diverter meanscauses the fluid of the protective layer to flow in a directiongenerally opposite to the direction of flow of the fluidic stream.

9. A fluidic device for sensing the presence or absence of an object andconnectable to a fluidic control element, said fluidic devicecomprising:

means defining a primary fluid supply passage terminating adjacent oneend in a primary supply orifice with the primary supply orifice beingcapable of discharging fluid therefrom in a primary fluid stream;

means defining a collector passage connectable to the fluidic controlelement and tenninating adjacent one end in a collector orifice, saidcollector orifice generally confronting said primary supply orifice andbeing spaced therefrom by a gap of predetermined length so that at leasta portion of the primary fluid stream discharged from said primarysupply orifice can traverse said gap and enter said collector orifice toprovide a first signal for the fluidic control element; and

means for converting a portion of said primary fluid stream into aprotective curtain of fluid extending along at least a portion of saidprimary fluid stream in a direction to avoid substantial impingementagainst said primary fluid stream said protective curtain of fluid atleast partially surrounding said fluid stream.

10. A fluidic device, comprising:

a collector having a collector passage therein, said collector passagehaving a collector inlet;

means including a discharge opening with the discharge opening beingspaced from the collector inlet by a gap for directing a substantiallyunconfined fluidic stream from the discharge opening across said gap tothe collector inlet; and

diverter means adjacent said collector inlet for intercepting a portionof the fluidic stream and converting at least some of said portion ofthe fluidic stream into a protective layer which extends along saidfluidic stream with the axis of flow of said protective layer extendinggenerally in the same direction as the axis of flow of the fluidicstream, the protective layer including a protective column extendingalong and substantially surrounding the fluidic stream.

11. A fluidic device, comprising:

a collector having a collector passage therein, said collector passagehaving a collector inlet;

means including a discharge opening with the discharge opening beingspaced from the collector inlet by a gap for directing a substantiallyunconfined fluidic stream from the discharge opening across said gap tothe collector inlet;

diverter means adjacent said collector inlet for intercepting a portionof the fluidic stream and converting at least some of said portion ofthe fluidic stream into a protective layer which extends along saidfluidic stream with the axis of flow of said protective layer extendinggenerally in the same direction as the axis of flow of the fluidicstream; and

a fluidic element connectable to the collector passage to receive atleast a portion of the fluid of the fluidic stream from the collectorpassage to provide a first signal to the fluidic element, the fluidicstream being disruptable by the placement of an object therein toprovide a second signal to the fluidic element.

1. In a fluidic device for sensing the presence or absence of an object,the combination of: a body member having first and second faces, saidfaces being generally confronting and spaced apart said body memberhaving a primary air supply passage therein connectable to a source ofprimary air under pressure, said primary air supply passage terminatingadjacent said first face in a primary supply orifice with the primaryair being discharged from the primary supply orifice in a primaryairstream; said body member having a collector passage therein, saidcollector passage having a collector orifice which is adjacent saidsecond face and which is spaced from said primary supply orifice, saidcollector orifice being arranged to receive air from the primaryairstream; and means defining a curved surface adjacent said collectororifice and in the path of said primary airstream for diverting aportion of the primary airstream into a generally tubular protective,air column extending along and at least substantially surrounding theprimary airstream to protect the latter against ambient air currents. 2.A combination as deFined in claim 1 wherein said last mentioned meansincludes a deflector member mounted on said body member, said deflectormember having said collector orifice therein and defining said curvedsurface.
 3. A combination as defined in claim 1 wherein said lastmentioned means causes the air of the protective column to flow in adirection generally opposite to the direction of air flow of the primaryairstream.
 4. In a fluidic system, the combination of: means defining aprimary fluid supply passage, said primary fluid supply passage defininga primary supply orifice which is capable of discharging fluid therefromin a primary fluid stream; means defining a collector passage, saidcollector passage defining a collector orifice which generally confrontssaid primary supply orifice and is spaced therefrom by a gap so that atleast a portion of the primary fluid stream discharged from said primarysupply orifice can travel across said gap to said collector orifice; andmeans defining a curved surface adjacent said collector orifice and inthe path of said primary fluid stream for diverting a portion of theprimary fluid stream into a generally tubular, protective, fluid columnextending along and at least substantially surrounding the primary fluidstream to protect the latter against ambient fluid currents.
 5. Acombination as defined in claim 4 wherein said curved surface surroundsthe collector orifice and defines a generally annular recess openingtoward said primary supply orifice.
 6. In a fluidic device for sensingthe presence or absence of an object and connectable to a fluidiccontrol element, the combination of: means defining a primary fluidsupply passage terminating adjacent one end in a primary supply orificewith the primary supply orifice being capable of discharging fluidtherefrom in a primary fluid stream; means defining a collector passageconnectable to the fluidic control element and terminating adjacent oneend in a collector orifice, said collector orifice generally confrontingsaid primary supply orifice and being spaced therefrom by a gap ofpredetermined length so that at least a portion of the primary fluidstream discharged from said primary supply orifice can traverse said gapand enter said collector orifice to provide a first signal for thefluidic control element; and means adjacent said collector orifice forconverting a portion of the primary airstream into a protective columnof fluid extending along and at least partially surrounding the primaryfluid stream to protect the latter against ambient air currents,disruption of the primary fluid stream for a predetermined periodproviding a second signal to the fluidic control element.
 7. A fluidicdevice, comprising: a collector having a collector passage therein, saidcollector passage having a collector inlet; means including a dischargeopening with the discharge opening being spaced from the collector inletby a gap for directing a substantially unconfined fluidic stream fromthe discharge opening across said gap to the collector inlet; anddiverter means adjacent said collector inlet for intercepting a portionof the fluidic stream and converting at least some of said portion ofthe fluidic stream into a protective layer which extends along and atleast partially surrounds said fluidic stream with the axis of flow ofsaid protective layer extending generally in the same direction as theaxis of flow of the fluidic stream.
 8. A fluidic device as defined inclaim 7 wherein said diverter means causes the fluid of the protectivelayer to flow in a direction generally opposite to the direction of flowof the fluidic stream.
 9. A fluidic device for sensing the presence orabsence of an object and connectable to a fluidic control element, saidfluidic device comprising: means defining a primary fluid supply passageterminating adjacent one end in a primary supply orifice with theprimary supply orifice being capable of discharging fluid therefrom in aprimary fluid stream; means defining a collector passage connectable tothe fluidic control element and terminating adjacent one end in acollector orifice, said collector orifice generally confronting saidprimary supply orifice and being spaced therefrom by a gap ofpredetermined length so that at least a portion of the primary fluidstream discharged from said primary supply orifice can traverse said gapand enter said collector orifice to provide a first signal for thefluidic control element; and means for converting a portion of saidprimary fluid stream into a protective curtain of fluid extending alongat least a portion of said primary fluid stream in a direction to avoidsubstantial impingement against said primary fluid stream saidprotective curtain of fluid at least partially surrounding said fluidstream.
 10. A fluidic device, comprising: a collector having a collectorpassage therein, said collector passage having a collector inlet; meansincluding a discharge opening with the discharge opening being spacedfrom the collector inlet by a gap for directing a substantiallyunconfined fluidic stream from the discharge opening across said gap tothe collector inlet; and diverter means adjacent said collector inletfor intercepting a portion of the fluidic stream and converting at leastsome of said portion of the fluidic stream into a protective layer whichextends along said fluidic stream with the axis of flow of saidprotective layer extending generally in the same direction as the axisof flow of the fluidic stream, the protective layer including aprotective column extending along and substantially surrounding thefluidic stream.
 11. A fluidic device, comprising: a collector having acollector passage therein, said collector passage having a collectorinlet; means including a discharge opening with the discharge openingbeing spaced from the collector inlet by a gap for directing asubstantially unconfined fluidic stream from the discharge openingacross said gap to the collector inlet; diverter means adjacent saidcollector inlet for intercepting a portion of the fluidic stream andconverting at least some of said portion of the fluidic stream into aprotective layer which extends along said fluidic stream with the axisof flow of said protective layer extending generally in the samedirection as the axis of flow of the fluidic stream; and a fluidicelement connectable to the collector passage to receive at least aportion of the fluid of the fluidic stream from the collector passage toprovide a first signal to the fluidic element, the fluidic stream beingdisruptable by the placement of an object therein to provide a secondsignal to the fluidic element.